Thanks 273. The clay is there for educational purposes, nothing else. It will continue to be used whenever I see the opportunity to learn something. Nice, non destructive, easily removable way to learn something you didn't know before.
Unless I can’t get paid to do it, I fill in the back of every guide. That dead area back there is just that. Dead space.
I learned a few months after I bought my bench that some of the head manufacturers were leaving the material out from behind the guide to increase the volume a bit.
You won’t find many competitive heads without the guide being filled in.